Linezolid treatment of ventriculoperitoneal shunt infection without implant removal

Ventriculoperitoneal shunt infection: insights from a single-center comparative analysis

Ventriculoperitoneal (VP) shunting is frequently associated with complications of which shunt-related infections are the most common. However, controversies still exist regarding the underlying factors. This study comparing peri-operative skin preparation agents was aimed at determining which factors among previously documented determinants of shunt infection are implicated in our practice setting. Fifty-four patients with hydrocephalus were allotted into two groups (Group I had pre- surgical skin preparation with povidone- iodine while Group II had pre- surgical skin preparation with 2% chlorhexidine gluconate-alcohol prior to VP shunting). The same brand and dose of prophylactic antibiotics were administered in both groups at induction of anaesthesia. Similar irrigation fluid constituted with similar antibiotics at the same concentration was used in both groups. Chhabra brand of VP shunt system as well as the same types of sutures was used for both groups. The patients were followed up over 6 months for VP shunt infection. Analysis of the data collected was done and p-value was set at ≤ 0.05. Of the 54 patients, 14 (25.9%) patients developed post-operative infections, with 9(64.3%) in Group I and the remaining 5(35.7%) in Group II. The infection rate for Group I (9 out of 30) was 30.0% while the infection rate for Group II (5 out of 24) was 20.8%. There was however no statistically significant difference in the rates of infection between both groups (p = 0.445). The occurrence of ventriculoperitoneal shunt infection was not found to be dependent on choice of the skin preparatory agent, cadre of the operating surgeon, duration of surgery, patients' gender, or body mass index (BMI). Findings from this study support previous recommendations that the choice of skin preparation agent for pre-operative skin antisepsis in VP shunting should simply be based on other factors such as the surgeon's preference, sound knowledge of the agent itself, its efficacy and cost. Type of study: Clinical research. Level of evidence: Level II.

Comparative analysis of linezolid, vancomycin, and hyperbaric oxygen therapies in a rat model of ventriculoperitoneal shunt infection

PURPOSE

Staphylococcus epidermidis is the most common causative microorganism of ventriculoperitoneal shunt infections. This study aimed to compare linezolid and vancomycin treatments and to examine the effect of these antibiotics alone and combined with hyperbaric oxygen therapy on the amount of bacterial colonies in the experimental S. epidermidis shunt infection model.

METHODS

A shunt catheter was placed in the cisterna magna of 49 adult male Wistar albino rats. The rats were randomly divided into seven groups, as follows: sterile control, infected control, vancomycin, linezolid, hyperbaric oxygen, vancomycin + hyperbaric oxygen, linezolid + hyperbaric oxygen. In all groups except the sterile control group, 0.2 ml 107 CFU/mL S. epidermidis was inoculated to the cisterna magna. Parenteral vancomycin was administered 40 mg/kg/day to the vancomycin groups, and 50 mg/kg/day of enteral linezolid to the linezolid groups. Hyperbaric oxygen groups were given 100% oxygen at a pressure of 2.4 ATA for 50 min a day. One day after the last treatment, colony quantities in the shunt catheters and CSF were analyzed.

RESULTS

The number of CSF colonies in the linezolid group was significantly lower than in the vancomycin group (p < 0.05). The number of CSF colonies in the linezolid + HBO group was significantly lower than in the vancomycin + HBO group (p < 0.05).

CONCLUSIONS

Linezolid treatment was found to be more effective than vancomycin in ventriculoperitoneal shunt infection caused by S. epidermidis. There was no statistical difference among other treatment groups. Hyperbaric oxygen therapy is shown to contribute to the sterilization of cultures.

Management of Ventriculoperitoneal Shunt Infections in Adults: Analysis of Risk Factors Associated With Treatment Failure

Background

Little is known regarding the optimal treatment of ventriculoperitoneal (VP) shunt infections in adults. Our aim was to assess the efficacy of treatment strategies and to identify factors that predict failure.

Methods

Retrospective, observational study of patients aged ≥12 years with VP shunt infections (1980 -2014). Therapeutic approaches were classified under 4 headings: only antibiotics (OA), one-stage shunt replacement (OSSR), two-stage shunt replacement (TSSR), and shunt removal without replacement (SR). The primary endpoint was failure of the treatment strategy, defined as the absence of definite cerebrospinal fluid (CSF) sterilization or related mortality. The parameters that predicted failure were analyzed using logistic regression.

Results

Of 108 episodes (51% male, median age 50 years), 86 were analyzed. Intravenous antibiotics were administered for a median of 19 days. Eighty episodes were treated using strategies that combined antibiotic and surgical treatment (37 TSSR, 24 SR, 19 OSSR) and 6 with OA. Failure occurred in 30% of episodes, mostly due to lack of CSF sterilization in OSSR and OA groups. Twelve percent died of related causes and 10% presented superinfection of the CSF temporary drainage/externalized peritoneal catheter. TSSR was the most effective strategy when VP shunt replacement was attempted. The only independent risk factor that predicted failure was retention of the VP shunt, regardless of the strategy.

Conclusions

This is the largest series of VP shunt infections in adults reported to date. VP shunt removal, particularly TSSR when the patient is shunt dependent, remains the optimal choice of treatment and does not increase morbidity.

Efficacy of postoperative antibiotic injection in and around ventriculoperitoneal shunt in reduction of shunt infection: A randomized controlled trial

OBJECTIVES

Infection is a common complication of ventriculoperitoneal (VP) shunt surgery. The incidence of shunt infection is still high despite routine administration of perioperative antibiotics. A lower incidence of shunt infection was observed when antibiotic-impregnated shunts (AIS) were used to treat hydrocephalus and a rapid cure was reported in cases of ventriculitis when antibiotics were injected into external ventricular drain (EVD). That is why we theorized that postoperative prophylactic injection of antibiotics in and around the shunt hardware would reduce the incidence of shunt infection.

PATIENTS AND METHODS

A randomized controlled clinical trial where 60 patients up to one year old, diagnosed with congenital hydrocephalus and submitted to VP shunt insertion, were randomly assigned to one of 3 groups. The treatment groups received the conventional perioperative antibiotics in addition to vancomycin and gentamicin injection in the reservoir and around the peritoneal catheter either once (group A) or twice (group B), while the control group (C) received only the conventional perioperative antibiotics. Cases were followed-up for up to 1 year.

RESULTS

The majority of patients were less than 1 month old. The follow-up period ranged from 2 to 12 months with a mean of 8.9 months. The mean duration of onset of infection after surgery was 30 days. Prematurity (p=0.00236), age less than one month (p<0.0001) and duration of surgery of 90 min or more (p<0.00001) were significant risk factors for postoperative shunt infection. Significantly more cases of shunt infection occurred within one month after surgery (p=0.021). The control group had significantly more cases of postoperative shunt infection than the treatment groups (p=0.0042).

CONCLUSIONS

In congenital hydrocephalus patients submitted to VP shunt insertion, injection of prophylactic vancomycin and gentamicin in and around the shunt hardware significantly reduced the incidence of postoperative shunt infection.

Efficacy of the novel oxazolidinone compound FYL-67 for preventing biofilm formation by Staphylococcus aureus

OBJECTIVES

Infections of hospitalized patients caused by biofilms formed by Staphylococcus aureus represent a major problem. Using in vitro and in vivo biofilm models, we evaluated the efficacy of the novel oxazolidinone FYL-67, by using linezolid (the only clinically approved oxazolidinone antibiotic) as a control, for inhibiting S. aureus biofilm formation.

METHODS

Antibiofilm activity was determined using strains of methicillin-susceptible S. aureus and methicillin-resistant S. aureus. We studied the mechanism(s) and pharmacodynamics of antibiofilm activity as follows: (i) effects of pre- and post-exposure to FYL-67 or linezolid on biofilm formation; (ii) the effect of FYL-67 on biofilm structure; (iii) the role of FYL-67 in biofilm composition; (iv) effects on cell morphology; and (v) efficacy of FYL-67 and linezolid using an in vivo murine model of catheter infection.

RESULTS

FYL-67 effectively inhibited biofilm formation using in vitro and in vivo assays.

CONCLUSIONS

Our data suggest that oxazolidinone compounds, such as FYL-67, may serve as antibiofilm agents.

Clinical update on linezolid in the treatment of Gram-positive bacterial infections

Gram-positive pathogens are a significant cause of morbidity and mortality in both community and health care settings. Glycopeptides have traditionally been the antibiotics of choice for multiresistant Gram-positive pathogens but there are problems with their use, including the emergence of glycopeptide-resistant strains, tissue penetration, and achieving and monitoring adequate serum levels. Newer antibiotics such as linezolid, a synthetic oxazolidinone, are available for the treatment of resistant Gram-positive bacteria. Linezolid is active against a wide range of Gram-positive bacteria and has been generally available for the treatment of Gram-positive infections since 2000. There are potential problems with linezolid use, including its bacteriostatic action and the relatively high incidence of reported adverse effects, particularly with long-term use. Long-term use may also be complicated by the development of resistance. However, linezolid has been shown to be clinically useful in the treatment of several serious infections where traditionally bacteriocidal agents have been required and many of its adverse effects are reversible on cessation. It has also been shown to be a cost-effective treatment option in several studies, with its high oral bioavailability allowing an early change from intravenous to oral formulations with consequent earlier patient discharge and lower inpatient costs.

Action of linezolid or vancomycin on biofilms in ventriculoperitoneal shunts in vitro

Cerebrospinal fluid (CSF) shunts used to treat hydrocephalus have an overall infection rate of about 10% of operations. The commonest causative bacteria are Staphylococcus epidermidis, followed by Staphylococcus aureus and enterococci. Major difficulties are encountered with nonsurgical treatment due to biofilm development in the shunt tubing and inability to achieve sufficiently high CSF drug levels by intravenous administration. Recently, three cases of S. epidermidis CSF shunt infection have been treated by intravenous linezolid without surgical shunt removal, and we therefore investigated vancomycin and linezolid against biofilms of these bacteria in vitro. A continuous-perfusion model of shunt catheter biofilms was used to establish mature (1-week) biofilms of Staphylococcus aureus, Staphylococcus epidermidis (both methicillin resistant [MRSA and MRSE]), Enterococcus faecalis, and Enterococcus faecium. They were then "treated" with either vancomycin or linezolid in concentrations achievable in CSF for 14 days. The biofilms were then monitored for 1 week for eradication and for regrowth. Enterococcal biofilms were not eradicated by either vancomycin or linezolid. Staphylococcal biofilms were eradicated by both antibiotics after 2 days and did not regrow. No resistance was seen. Linezolid at concentrations achievable by intravenous or oral administration was able to eradicate biofilms of both S. epidermidis (MRSE) and S. aureus (MRSA). Neither vancomycin at concentrations achievable by intrathecal administration nor linezolid was able to eradicate enterococcal biofilms. It is hoped that these in vitro results will stimulate further clinical trials with linezolid, avoiding surgical shunt removal.

Imaging diagnosis--Ventriculo-peritoneal shunt associated infection in a dog

Ventriculo-peritoneal shunting is a surgical treatment for hydrocephalus. Complications of this procedure are not well described in dogs. The most common complication in humans is infection, which can be fatal if not diagnosed and treated quickly. We describe the magnetic resonance (MR) imaging characteristics of a shunt-associated cerebral infection in a dog. The MR features of the infection included hyperintensity of the lining of the ventricular system visible on a T2-weighted FLAIR sequence and marked linear contrast enhancement of the ependymal layer on T1-weighted sequences, similar to that described in people.

Update on the appropriate use of linezolid in clinical practice

Multi-antibiotic resistant Gram-positive cocci, which include Staphylococcus aureus, the coagulase-negative staphylococcal group, Enterococcus faecalis and Enterococcus faecium, and other streptococci, represent emerging pathogens especially in the setting of the immunocompromised, hospitalized patients, in particular when surgery, invasive procedures, or prosthetic implants are of concern, patients are admitted in intensive care units, or underlying chronic disorders and immunodeficiency are of concern, and broad-spectrum antibiotics or immunosuppressive drugs are widely administered. During the recent years, the phenomenon of multiresistant Gram-positive cocci is spreading to the community, where the retrieval of such microorganism is progressively increasing. The spectrum of available antimicrobial compounds for an effective management of these relevant infections is significantly impaired in selection and clinical efficacy by the emerging and spread of methicillin-resistant and more recently glycopeptide-resistant Gram-positive microbial strains. The first oxazolidinone derivative linezolid, together with the recently licensed quinupristin–dalfopristin, daptomycin, and tigecycline, followed by a number of glycopeptides, fluoroquinolones, and other experimental compounds on the pipeline, represent an effective response to the great majority of these concerns, due to their innovative mechanisms of action, their maintained or enhanced activity against multiresistant pathogens, their effective pharmacokinetic/pharmacodynamic properties, their frequent possibility of synergistic activity with other compounds effective against Gram-positive pathogens, and a diffuse potential for a safe and easy administration, also when compromised patients are of concern. The main problems related to the epidemiological and clinical features of multiresistant Gram-positive infection, the potential clinical indications of all recently available compounds compared with the standard of care of treatment of resistant Gram-positive infections, and updated data on efficacy and tolerability of linezolid as the golden standard compound for vancomycin-resistant Gram-positive cocci in multiple clinical situations, are outlined and updated on the ground of an extensive review of all the available, recent evidences coming from the international literature.

Linezolid treatment of shunt-related cerebrospinal fluid infections in children

OBJECT

The emergence of multidrug-resistant bacteria as a cause of ventriculoperitoneal (VP) shunt infection is a disconcerting phenomenon that often requires the use of alternative antimicrobial agents due to resistance against commonly used medications. Linezolid, a member of a new class of antimicrobial agents, has good activity against virtually all important gram-positive pathogens, including multidrug-resistant gram-positive pathogens. The object of this article is to report a single-center experience with linezolid treatment in 6 young patients with VP shunt infections caused by drug-resistant strains.

METHODS

The authors reviewed the records of 6 pediatric patients who developed VP shunt infection and in whom initial antimicrobial treatment regimens, including vancomycin, either failed or were associated with vancomycin-resistant enterococcus. All 6 patients were treated at their hospital between July 1, 2008, and June 29, 2009. The patients' demographic and clinical characteristics, underlying diseases, clinical manifestations, laboratory results, and various treatment modalities used before linezolid therapy were evaluated.

RESULTS

The 6 patients included were 2 boys and 4 girls with a mean (+/- SD) age of 11.83 +/- 12 months (range 4-36 months). Five patients had acquired an infection within 4 months (mean 7.50 +/- 13.51 months, range 1-35 months) after shunt insertion. Four patients were treated with external ventricular drainage. Two patients' parents refused to allow shunt removal and placement of an external ventricular drain. The CSF was clear of bacterial growth within a mean of 3.67 +/- 1.36 days (range 2-6 days) after initiation of linezolid treatment. The mean duration of linezolid treatment was 18.17 +/- 3.31 days (range 14-21 days). Microbiological clearance of CSF and clinical cure were achieved in all patients. No laboratory or clinical side effects were observed during the treatment period. The mean length of hospital stay was 22.8 +/- 4.96 days (range 17-28 days).

CONCLUSIONS

Linezolid could be an appropriate treatment alternative in children with ventriculostomy-related CSF infections caused by drug-resistant strains, including cases in which shunt removal is not an option. Well-designed prospective studies providing additional information on linezolid levels in plasma and CSF are necessary to confirm the authors' observations.

Successful treatment of methicillin-resistant Staphylococcus aureus meningitis using linezolid without removal of intrathecal infusion pump

✓ Infection of an intrathecal pump system is a rare but serious complication and usually leads to the removal of the pump. The authors report the first case of methicillin-resistant Staphylococcus aureus (MRSA) meningitis in a patient with such a pump successfully treated with linezolid without the need for removal of the intrathecal pump. A 77-year-old woman with cervical myelopathy underwent implantation of an intrathecal pump system for baclofen administration. Two weeks after the procedure she developed meningitis caused by MRSA as isolated in cerebrospinal fluid (CSF) cultures, blood samples, and serum obtained from the pump pouch. Clinically she presented with meningism, somnolence, and signs of sepsis. When a combined intravenous antibiotic treatment regimen of vancomycin and rifampicin resulted in no clinical improvement, that regimen was discontinued and linezolid was administered intravenously as monotherapy. Within 3 days clinical and laboratory findings showed significant improvement. After 1 week of linezolid treatment, blood and CSF cultures were sterile. Intravenous treatment was administered for a total of 3 weeks, after which the patient was treated with oral linezolid for 3 months. During 18 months of follow-up, no new clinical or laboratory signs of infection were observed. These results confirm previous reports of the efficacy of linezolid for the treatment of severe infections of the central nervous system caused by multidrug-resistant Gram-positive bacteria, especially postneurosurgical infections.